FYI - Avast thinks the uninstaller.exe hosts malware.
The “malware scanners” often confuse the NSIS installer/uninstaller signatures as being malware, because some malware uses NSIS installer/uninstaller. When enough users vote the notepad++ executable or installer/uninstaller safe, such warnings usually go away.
(That’s one of my biggest frustrations with such anti-malware ratings: they give an application a black mark without investigating first. Which makes them useless, because then people just learn to ignore their warnings since they give so many false positives)